Replaceable and interchangeable dies for crimping tools



Sept. 4 1956 M. LAZAR ET AL REPLACEABLE AND INTERCHANGEABLE DIES FOR CRIMFING TOOLS Filed Sept. 4, 1953 Tic- .1.

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p 1956 M. LAZAR ETAL REPLACEABLE AND INTERCHANGEABLE DIES FOR CRIMPING TOOLS 2 Sheets-Sheet 2 Filed Sept. 4, 1953 vivvflw INVENTORS United States Patent O REPLACEABLE AND INTERCHANGEABLE DIES FOR CRIB/[PIN G TOOLS Michael Lazar, Bronx, N. Y., and Richard G. Wallenhorst, Norwalk, Conn., assignors to Burndy Engineering Co. Inc., a corporation of New York Application September 4, 1953, Serial N 0. 378,630 2 Claims. (CI. 81-15) Our invention relates to a die holder, and to removable dies used on crimping tools to permit variations in crimps accomplished by a single tool.

High hydraulic forces are exerted on the dies requiring a large anvil area. When the forces are released, the dies are moved away from the work piece which may be an electrical connection, to permit removal therefrom. The die holders must resist this removal pressure. Furthermore, the dies must be rigidly supported to insure proper alignment in the crimping operation, while providing the necessary anvil area. Additionally, the dies must be easily inserted and removed from the holders without the use of auxiliary tools.

In installations on overhead electrical systems, the dies are supported at a distance about 4 feet from the operator to provide a factor of safety when working on hot or energized lines. The press which operates the dies is moved along the conductors from one crimping position to another. The weight of the tool will often cause the head die to be struck sidewise, tending to loose-n it. Moreover, the dies must be insertable and removable by gloved hands.

Accordingly, the principal object of our invention is to provide a die holder that will quickly and easily permit a die to be inserted and automatically secured therein; that will prevent the die parts from sticking .to the work piece and being accidentally removed therewith; that will not require two hands for operation; that cannot be easily broken or damaged; that will accommodate high stresses; that will occupy a minimum of space; that may be operated by gloved hands; that will permit a die to be easily removed for insertion of another die part.

These and other objects are accomplished and our new results obtained as will be apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawing, in which:

Fig. 1 is a side elevation of a compressing tool containing our invention;

Fig. 2 is an enlarged view of the head portion, partly in section;

Fig. 3 is an enlarged front elevation of the head portion, partly in section;

Figs. 4, 5 and 6 are top, side, and sectional views of the die part.

In the drawing, reference numeral 10 designates a hydraulic compression tool of the type illustrated in Patent No. 2,309,605 and employed by us to illustrate the invention.

We have adapted this tool to overhead hot line work by providing a hook-shaped head 12 forming a mouth 14 through which the attached electrical connections may be laterally withdrawn. The tool is further characterized by a body 16, handle 18 and lever 20 for operating the ram 22, as is described and illustrated in greater detail in the aforesaid patent.

The die parts 24 are made identical, the shape of the The die part 24 is securely supported by die holders.

26 and 28 in the head and ram, respectively. To provide a large anvil area for the dies, to insure maximum resistance to pull out forces, and to obtain close alignment of the dies and die holders, a T-shaped die head 30, such as is illustrated 'in Fig. 5 was found to give the best results. The die holders are provided with T-sh'aped slots 32 and 34, respectively, to accommodate the dies.

The working surface of each die is designed to produce the type of crimp required by the particular type of connector, and may comprise a semicircular crimping bead 36, provided with recesses 38 at the ends thereof to accommodate the flow of the crimped metal.

The upper face of the die is formed with tapering grooves 42 at each side to cam a pin or ball check into the centrally positioned recess 44, to securely lock the die to the holder.

in the hook-shaped head :12 of the press 10, the die holder .26 is provided with such a pin check 46, which projects from a hole 48 in the T-shaped die head slot 32. The pin check has a cylindrical guiding sect-ion 4'9 and terminates in a head portion '50 which is loosely fitted in the chamber 52 of the head. A spring 54 in the chamber presses the pin check against a lever '56 positioned in a peripheral undercut 58. The pin check is made entirely by turning so that any rotation of the piece in the hole in the head will not cause jamming of the mechanism. The lever is pivoted at 60 in the slot 62 formed in the head 12, and terminates in a finger piece 64 which is T-shaped and serrated so that the finger will not slip off easily. Thus, when the finger urges the lever downwardly, the pin check is lifted from the die against the action of spring 54, thus freeing the die from the holder. Due to the shape of the end of the tapered pin and the chamfer on the die recess, the pin cannot be forced out of the recess by pushing on the die.

To compensate for manufacturing tolerances and to hold the lever 56 upwards against the top of the slot 62 in the head .12, a release lever hair spring 63 is provided. One end of spring 63 engages the lever 56 through a hole 61 in the lever. The spring is coiled around the pin in the pivot 60, and the remaining end bears against the top of the head die holder 26. Sidewise pressure is exerted by the coil on the side of the lever 56 and on the side of the slot 62 to take out all sidewise shake of the lever.

The lower die part secured in the ram die holder is not subject to the side swiping forces that may involve the die part secured in the head. It is suflicient for our device to provide the ram head with the holder 28 which contains a ball check 66 urged in the seat 68 by the spring 70. Set screws .72 or pins in the ram hold the lower die holder, ball check, and ball check spring in place. Screws 74 similarly hold the upper die holder to the hook head 12. The ball check 66, the pin check 46, and the die recess 44 were so designed as to permit either die in the two-piece die sets to be used in either holder. The T-shaped slots of the holders are identical for the same reason.

In the foregoing, we have provided the following advantages: head and ram dies that are identical which simplifies production and assembly; dies that are simply installed by pressing into place; a head die that cannot he accidentally knocked out of alignment; head and ram dies that are securely attached .to their respective holders and cannot stick to the connector or work piece; head and ram dies that are accurately located; a head die that can be removed with one hand, if rubber gloves are worn; a pin check that is operated by a pushing instead of a pulling motion; a tool head and release lever that can be easily insulated; a T-sh'aped interlock instead of .a dove-tail for maximum anvil area with built;

a ram die that is easily removed by pushing it out of the slot; a pin check mechanism that is fully enclosed;

"a die release lever that is not easily broken off; a die interlock which prevents rocking of the dies as is sometimes experienced with cylindrical dies; a die release lever provided with a hair spring that holds the lever firmly at other ways without departing from the spirit of our invention, and, therefore, we claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which objects of our invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

We claim:

1. A connector indenting tool having a stationary jaw provided with an integrally extending handle and a movable jaw, each jaw provided with a readily removable die part, means for moving said movable jaw member with sufiicient force towards said stationary jaw member to indent an electrical connector, said stationary jaw and die part provided with a spring loaded pin operated check, and a finger piece pivoted to the stationary jaw and engaging said pin to move it in a planenormal to the longitudinal axis of the electrical connetor for releasing said die .part.

2. The tool of claim 1, wherein each die part is formed identically with a pin receiving recess and a tapered groove extending from the edge of the die part towards said recess for carnming the pin into the recess from the edge of the die.

References Cited in the file of this patent UNITED STATES PATENTS 1,210,911 Dav-is Ian. 2, 19-17 1,294,715 Shu'ltz Feb. 18, 1919 2,043,550 Mumbrauer June 9, 1936 2,615,664 Reeves Oct. 28, 1952 

